Flexible shaft putter



July 7, 1970 J. w. BAYMILLER 3,519,270

FLEXIBLE SHAFT PUTTER Filed March 4, 1968 Approx/moral length of shaft is substanflbI/y inflexible F 6. F G. 2 F G. 3

8 //8 /8 A pprox/maleb lang/l; of shaft is flexible //v vs/vron JOHN W BAY/MILLER United States Patent 3,519,270 FLEXIBLE SHAFT PUTTER John W. Baymiller, 1708 Lititz Pike, Lancaster, Pa. 17601 Filed Mar. 4, 1968, Ser. No. 710,002 Int. Cl. A631) 53/12 US. Cl. 273--80 12 Claims ABSTRACT OF THE DISCLOSURE A golf putter is provided which is uniformly flexible over a portion of the shaft adjacent the head of the putter. The shaft is flexible only over the lower onethird of its length, with the upper two-thirds being of conventional construction. The head of the putter is so shaped and the weight thereof so distributed that the center of percussion coincides as nearly as possible with the geometric center of the club face.

FIELD OF THE INVENTION The present invention relates, in general, to golf clubs and their construction and, more particularly, to a putter having a flexible shaft.

BACKGROUND OF THE INVENTION As is Well known to golfers, the degree of muscular sensitivity required for successful putting is much higher than that used in other golf strokes. The putting stroke is a delicate effort compared to that used in swinging the other clubs, and successful execution depends greatly on muscular feel, or kinesthesia, in locating and controlling the movement of the putter head. No matter how accurately a golfer is able to determine the line which a golf ball must follow and the distance which it must move, the muscles and nerves must react precisely to propel the putter head not only along the correct line, but with the exact degree of force required by the distance the ball must travel. It is in this latter respect that putting differs most obviously from the strokes generally executed with other clubs, although the putting stroke also requires greater directional accuracy than other types of strokes.

Many attempts have been made to provide putters which increase the accuracy of a putting stroke, both as to direction and distance. In such prior attempts, how ever, the primary emphasis has been on direction, and thus numerous ideas for putter constructions have been put forth, directed to improving the directional accuracy of a putt. To this end, flexible putters have been suggested, such devices being provided with pivots or hinges whereby a portion of the club may be held immovable while the other part swings along the desired line. However, these arrangements do not fulfill the requirement for accuracy in the length of a putt, although they may provide some directional accuracy.

Flexible golf clubs have also been suggested for strokes other than putting, and to this end clubs have been produced with shafts which are flexible along their full length, or which are provided with sections of reduced cross section which will bend to provide the desired flexibility. However, such clubs are not suitable for putting, for the flexibility provided by these arrangements is designed primarily to produce a whip-like action which will increase the distance which a ball can be hit, but which do not improve the feel of the club in the manner required for putting accuracy. Further, a fully flexible shaft of this type will not permit the directonal accuracy required for putting.

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SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a putter having a shaft which is uniformly flexible over a portion of its length, thereby providing greater precision in the execution of putting strokes than was possible with prior devices.

In carrying out the present invention, a putter shaft is constructed having approximately the lower third of the total shaft length made flexible, with the remaining two thirds being of conventional construction. The flexibility of the lower portion of the shaft is uniform along that portion of the shaft in order to provide the proper control. The putter head must be mounted so that its center of percussion is near the geometric center of the face, so that when the ball is struck at this point there will be no turning moment produced in the head. Since, under present golfing regulations, the shaft of a putter must be of circular cross section, it is contemplated that the present invention utilize a flexible rod or tube having a prescribed range of deflection. It has been found that for best results, the flexibilty of the shaft should be such that a deflection of between one fourth of an inch and one inch will be produced when a twelve inch section of the shaft is held horizontally, is fixed at one end and is weighted at the other end with an eight ounce weight.

BRIEF DESCRIPTION OF THE DRAWINGS Further objects and features of the invention will best be understood and appreciated from the following detailed description of a preferred embodiment thereof, selected for purposes of illustration and shown in the accompanying drawings, in which:

FIG. 1 is a diagrammatic illustration of a golf putter made in accordance with the present invention;

FIG. 2 is a partial side view of the club of FIG. 1; and

FIG. 3 is a diagrammatic illustration of the physical characteristics of the flexible portion of the club of FIG. 1.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to FIG. 1, there is indicated generally at 10 a flexible shaft putter made in accordance with the present invention. The putter includes a conventional handle, or grip, portion 12 supported on a substantially inflexible shaft portion 14, also of conventional construction. The handle may be formed on or as a part of the stiff shaft portion 14, and may be molded, wrapped with a strip material, or may be fashioned in any known and conventional manner.

In the illustrated embodiment, shaft 14 tapers at 16 to a small diameter, to form a flexible portion 18 which extends approximately the lower one third of the club length. A putting head 20 is affixed to the lower end of the shaft portion 18, the shaft being connected at the upper surface and at approximately the center of the club head, in a heel to toe direction. Portion 18 of the club 10 is abnormally flexible when its stiffness is compared to conventional golf club shafts; that is, portion 18 has a deflection of about one half an inch when a 12 inch section of this portion is held fixed at one end in a horizontal position and weighted at the other end with a Weight of approximately 8 ounces. As a comparison, the maximum deflection of some conventional shafts, such as the lighter ones used in ladies clubs, is, under these same conditions, less than one eighth of an inch. Such conventional shafts are too stiff, and are not suitable for use in the present invention. The flexible portion 18 of the shaft should not exceed about one third of the total shaft length, for when it does exceed this proportion, control of putting, particularly of putting distance, suffers.

According to United States Golf Association regulations, the shaft of a putter must be of circular cross section; therefore, the preferred configuration of portion 18 of the shaft is that of a rod or tube having a continuous outer surface. Any composition of material for this flexible portion may be used, provided it has the deflection characteristics required for the present invention.

The particular amount of deflection may vary over a considerable range, and the most desirable value will be dependent upon the putting style and particular likes and dislikes of the individual golfer. As illustrated in FIG. 3, the deflection of shaft portion 18 is indicated at D. This deflection is the distance which the end of the flexible portion drops below the horizontal when the shaft is fixed at one end and weighted at the other end in the manner of a cantilever. This distance preferably is in the range of about one quarter of an inch to one inch, with one half inch to five eighths inch being the preferred range. At values below about one quarter of an inch, the shaft is too stiff to provide the sensitivity and response desired, while at values of deflection above one inch, the club head becomes so loose with respect to the handle that its use is questionable.

As has been noted, the flexible portion extends approximately one third the total length of the conventional putter shaft length, and for this reason the deflection characteristics have been given in terms of a shaft portion length of 12 inches, putters generally being about 36 inches in length. However, it should be noted that the specified deflection of between one quarter inch and one inch should be the same for any length of this abnormally flexible portion 18, whether the flexible portion is the full one third of the total shaft length, or less than one third. Thus, the degree of flexibility of portion 18 must be adjusted as its length is varied. It is the amount of actual deflection of the flexible portion of the shaft and the location of this portion near the head, which provides the sense of feel in the present invention.

It has been found that the desired degree of flexibility can be attained when a 12 inch section of solid tempered steel rod one eighth inch in diameter is used for portion 18 of the shaft. Where less than a 12 inch length is used, the diameter may have to be reduced or the characteristics of the steel varied to obtain the desired results. Although a steel shaft has been used as an example here, it will be apparent that glass fiber or other suitable materials may be used.

Although the shaft has been illustrated as being reduced in diameter from the conventional shaft portion 14 to form the flexible portion 18, it will be apparent that the flexibility can be attained by some other means, as by a change in material or a change in the treatment of the material used for portion 14. Portions 14 and 18 of the shaft may be connected in any convenient manner, the particular method used not forming a part of this invention.

To obtain optimum results with the flexible shaft putter, it has been found that a particular head construction should be used. The putter head should be so shaped and the weight thereof so distributed that the center of percussion approximately coincides with the geometric center of the face, which is usually the desired striking point. When a golf ball is struck by this point on the putter head, there will be no turning moment produced in the shaft, and the greatest amount of kinetic energy will be transferred from the moving head to the ball. Since a precise amount of kinetic energy has been generated in the putter head by reason of the sensitivity provided to th clube used by the flexible shaft, the full benefits of the use of such a shaft will be realized only when the head is properly constructed; otherwise, the precision will be lost.

The simplest method of locating the center of percussion on a putter face is to hold the club between the thumb and forefinger of one hand about two inches down from the upper end of the grip, or handle, portion. The knuckle of the thumb holding the club is placed firmly against the holders ear. Then, with a tack hammer or similar tool, the holder taps lightly over the face of the club until the spot is located where the least vibration and tinny sound are experienced through the ear contact. This spot is the center of percussion, and is illustrated at 22 in FIG. 1. As illustrated, this center of percussion coincides with the geometric center of the face. If the center of percussion is not located at the desired striking point on the face, ball contact at this striking point will produce a turning of the head, with the abovenoted loss of kinetic energy and thus of putting accuracy. Thus, the head used in combination with the flexible shaft must be carefully designed to meet the foregoing requirements.

It should be noted that the flexible shaft construction of the present invention is such that it produces a continuous bending along its length. This bending flexibility is, in the preferred embodiment, uniform in all radial directions from the axis of the shaft, and this permits deflection in any direction of the head end of shaft; it is not hinged or elbow joint type of flexibility, nor is the shaft bendable in merely a single direction. As illustrated in FIG. 3, the deflection of the putter head produces bending at each point along the length of the flexible portion of the shaft. The amount of bending at each such point is dependent upon the degree of flexibility of the shaft at that point, and this degree may be carefully regulated by proper selection and treatment of the materials used in making the shaft. It will be apparent that the degree of flexibility may be constant throughout the length of portion 18 of the shaft, or may vary in accordance with the desire of the particular user. It may be found desirable, for example, to construct the flexible portion with a taper to produce a continuously increasing degree of flexibility from the upper end of portion 18 to the head 20. Many variations in the degree of flexibility will be possible, within the scope of the present invention, although it is preferred that the total deflection of the head under the conditions described above remain within the given range. Further, the construction should be such that the center of gravity of the club remains at or near the head in order to provide the proper feel in the swing of the club. For this reason, a relatively heavy head is normally pro vided.

Thus, there has been provided a golf putter having a flexible portion which extends over approximately one third of its length, or less. The flexible portion of the shaft increases the accuracy of putting by improving the responsiveness of the club to the golfer. It will be apparent to those skilled in the art that many modifications and changes may be made in the basic concepts herein described. Such modifications will fall within the true spirit and scope of the invention as defined by the following claims.

I claim:

1. A conventional golf putter having a putting head and a shaft attached thereto, the improvement comprising a flexible portion in said shaft adjacent said putting head and extending approximately one-third the length of said shaft, the remainder of said shaft being substantially inflexible, said flexible portion having a continuous exterior surface and a degree of flexibility which will produce a head deflection of not less than about one-fourth inch and not more than about one inch when said shaft is held by its inflexible portion in a horizontal position, said putting head including a face portion for striking a ball, said head being so constructed that its center of percussion approximately coincides with the geometric center of said face portion.

2. The putter of claim 1, wherein said flexible portion is tubular.

3. The putter of claim 1, wherein said flexible portion is a rod.

4. The putter of calim 1, wherein said flexible portion is uniformly bendable, whereby it is capable of being deflected in any direction away from its axis.

5. The putter of claim 4, wherein said flexible portion has an equal degree of flexibility at each point along its length, whereby the deflection at said head will be distributed along the length of said flexible portion.

6. The putter of claim 4, wherein said flexible portion has a degree of flexibility which increases progressively from the upper end thereof toward the club head end thereof.

7. The putter of claim 1, wherein said flexible portion is continuously bendable along its length, whereby the deflection of said head will be distributed along the length of said flexible portion.

8. The putter of claim 1, wherein said flexible shaft portion has a degree of flexibility which will produce, when one end of a twelve inch length of said flexible portion is loaded with an eight ounce weight, a deflection at one end of not less than one-fourth inch and not more than one inch when the other end of said flexible portion is flexed in a horizontal position.

9. The putter of claim 8, wherein said flexible shaft portion is continuously and uniformly bendable throughout its length.

10. The putter of claim 9, wherein each point in said flexible shaft portion has a constant degree of flexibility.

11. The putter of claim 9, wherein said flexible shaft portion has a degree of flexibility which increases progressively from the upper end thereof to the club head end thereof.

12. In a conventional golf putter having a putting head and a shaft attached thereto, the improvement comprising a uniformly flexible portion in said shaft adjacent said putting head to provide enhanced sensitivity to club head position and speed when said club is swung in a putting stroke, said flexible portion extending approximately onethird the length of said shaft from said head with the remainder of said shaft being substantially inflexible, said flexible portion having a continuous exterior surface and a degree of flexibility which will produce a deflection of approximately one-half inch when the putter shaft is held in a horizontal position at its inflexible portion and loaded with an eight-ounce weight at its head end, and said putting head including a face portion for striking a ball, said head benig so constructed that its center of percussion approximately coincides with the geometric center of said face portion.

References Cited UNITED STATES PATENTS 1,670,530 5/1928 Cowdery 273 1,675,437 7/1928 Waldron 273-80 2,066,962 l/l937 Cross 27380 1,529,305 3/1925 Gatke 273-193 X 1,670,531 5/1928 Cowdery 27380 1,974,389 9/1934 Cowdery 273-80 2,341,053 2/1944 Mason 27380 X 3,341,202 9/1967 Stars 273-77 3,428,325 2/1969 Atkinson 273-l93 X FOREIGN PATENTS 854,911 11/1952 Germany.

22,968 1903 Great Britain. 20,726 1908 Great Britain. 378,295 8/ 1932 Great Britain.

RICHARD C. PINKMAN, Primary Examiner R. I. APLEY, Assistant Examiner UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent -No. 3, 519. 270 Dated July 7, 1970 In fls) John W. Baymiller It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 8, line 5, insert --said-- before one end" at beginning of line;

Claim 8, line 7, "fiexed" should be --fixed--.

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